Television

Oh, I completely misremembered. I'm really sorry: it was Dahl who loathed the 1971 film, and Wilder put a lot of his own feedback into the role.

From The Guardian:

Dahl himself would be exasperated over the 1971 film’s endurance. Though he was nominally billed as its screenwriter, his original adaptation was scarcely detectable beneath all manner of uncredited rewrites, and he was vocal in his disdain for the result, Wilder and all. His list of grievances was long: Dahl had wanted the arch British peculiarity of Spike Milligan or Peter Sellers for Wonka, he was unhappy with the film’s foregrounding of Wonka over Charlie, he resented plot alterations and additions that muddied the cautionary neatness of his original tale, and he wasn’t a fan of Leslie Bricusse and Anthony Newley’s perky song score.

Honestly, that makes me feel even shittier about the AI Gene Wilder now.